State of the art engines have thermal efficiencies in the range of 30 to 40%. This is due to heat lost by system cooling, friction of moving parts and energy lost in exhaust gases. In order to meet atmospheric emission standards additional energy is used to condition exhaust gases for reducing the toxicity.
Most engines use the internal combustion process. Steam engines use external combustion. Gas turbines operate with pressurized gases at very high temperatures. The turbines have a very high power to weight ratio but are not good for partial loads; they are very costly because of high temperatures and speeds of operation. Jet engines use gas turbines for propulsion. Turbofan engines are more efficient due to pick up of heat from the shell of the jet engine. Engines operate with increasing entropy due to irreversible heat transfer processes during operation of cooling systems, exhaust systems and accessories. Some engines internally provide power from gas turbines with exhaust gases to drive air compressors to increase the density of combustion air and to increase the mass of Oxygen in the air introduced into the engine for increased power output. Operating at higher altitudes aspirating engines produce less power. All engines require special considerations for materials used for internals subjected to high temperatures and pressures. Bearing and other moving parts are subject to short term high temperature yield stresses, short term ultimate yield, rupture strength, creep strength, relaxation strength, high temperature endurance limit, thermal expansion, corrosion and failures due to fatigue and natural frequencies of operation.
The primary object of this invention is to substantially reduce the cost of manufacture and operation of an energy-producing system with less impact on the environment. Specifically the following objects are cited:                a. Conserve energy of fuel combustion, compressed air and unburned fuel instead of discharging it through coolants and high temperature exhausts;        b. Conserve energy remaining in expanded gases issuing from a work-producing zone by circulating expanded gases in a closed loop with gaseous combustion products exhausted;        c. Maximize combustion of fuel and preferably obtain complete combustion with reduced flame temperature, so products of combustion contain only traces of Hydrocarbons and Carbon Monoxide and Oxides of Nitrogen;        d. Eliminate or minimize the need for treating exhaust gases for toxicity and noise.        e. Operate present art combustors with modifications to function as more efficient adiabatic power systems.        f. Use wind energy and/or solar energy to provide compressed air, including heated compressed air, with or without combustion or other uses in the invention.        